1. Field of the Invention
The invention relates to a film reader and, more particularly, to a film reader which records the picture image, on a film, onto a repetitively recordable and erasable information storage body, and observes the image on this information storage body.
2. Description of the Prior Art
An information storage body, as employed in the invention, uses an electricromic material, which changes color as a result of a change in its color absorption characteristic due to the conduction of electric current, and this condition is maintained for a long time even after the interruption of the conduction, and has a property (hereinafter called "electrocromy phenomenon"), depending on the electrical polarity, such as reversibly fading out, or returning to the original color, due to the conduction of the reverse polarity with respect to the former conduction. The degree of the color change corresponds to amount of conduction of the electric current within the range up to the saturation. The mechanism to generate the electrocromy phenomenon is not necessarily a single one. However, in many cases, it is understood as the so-called oxidation-reduction reaction of an electrolyte and a coloring substance. In this case, the electrolyte and coloring substance are not necessarily separated, from a material viewpoint. It may be possible that the coloring substance and the electrolyte are the same substance. Further, from another standpoint, the phenomenon is considered as the change in the light absorption characteristic due to the injection of an injection electron into the color center, similar to the case of photocromic material. Actually, the electrocromy phenomenon is understood to be derived as a result of the combination of the above two.
Since the electrocromy phenomenon serves to electrically change the color, which a material possesses inherently, the combination of colors varies. Further, since the characteristic of a material as to whether it transmits, reflects or scatters the light is not decided by the material's own property, but rather by the forming method of an information storage body having the electrocromic material, when it is used as a display element, either a light transmissive type or a light reflective type is available for use.
The study of the electrocromy phenomenon has become brisk in recent years, because various applications of the phenomenon are considered possible from the above constitutions of the mechanism and the aforementioned variety, and further from the storage characteristic, that the coloring is maintained from the initiation of the coloring to the fading out thereof, and from the fact that there is a material whose coloring is transmitted, corresponding to the impressed voltage value.
The range of materials showing the electrocromy phenomenon is wide and includes either organic or non-organic materials. These materials are all applicable to the invention. The known materials are indicated in the United Kingdom Pat. No. 1,186,541, for example.